What is ultrasound?
Ultrasound is like an ordinary sound except it has a frequency (or pitch) higher than human beings can hear. When sent into the body from a transducer resting on a patient’s skin, the sound is reflected off internal structures. The returning echoes are received by the transducer and converted by an electronic instrument into an image of the internal structures on a viewing screen. These continually changing images can be recorded on film, paper, videotape, or computer. Diagnostic ultrasound imaging is commonly called sonography or ultrasonography.
Why should I have an ultrasound exam?
There are many reasons for examining the abdomen with ultrasound. Among the more common reasons are:
To look for causes of lower abdominal pain, including appendicitis, inflammation of the small and large intestines, and hernias;
To look for abnormalities that may be present in the abdominal organs, such as masses or enlargements;
To evaluate the nature of a mass that may have been felt by the examining doctor or seen on other radiological exams;
To evaluate for enlargement of the liver or spleen;
To determine the cause of kidney failure, such as kidney disease, obstruction of the kidneys, or blockage of the kidneys’ blood vessels;
To evaluate for the cause of jaundice or abnormal liver enzymes;
To look for enlargements (aneurysms) of the abdominal aorta; and
To evaluate for problems of flow in the blood vessels of the various abdominal organs.
An ultrasound examination may not provide all the information your doctor needs. In these cases, additional studies may be required.
Are there any special
preparations for the exam?
You should refrain from eating, drinking, smoking, or chewing gum for 8 hours prior to the exam. This is because these actions increase the amount of abdominal gas preventing an adequate ultrasound examination. Keep your urinary bladder full by drinking enough water.
Will it hurt?
There is no pain involved in an ultrasound examination of your abdomen. The transducer is placed on the skin surface after a gel is applied to your abdomen to provide better contact. The gel may feel cool and may temporarily stain clothes, so you may want to wear easily washable clothing. The room is usually darkened during the examination.
How long will it take?
The length of time needed for the examination varies with the complexity of the exam and the specific reasons for which it was requested. After the exam, you can safely drive home and eat and drink normally.
Who will perform the exam?
It is always better for a radiologist who has good experience in ultrasound to perform the exam. He or she will also examine you to confirm or resolve uncertain or unclear findings.
The common causes of lower abdominal
pain in women are as follows:
Causes related to the womb such as:
Fibroids
Other tumours of the womb
Pregnancy related causes such as:
Molar pregnancy
Multiple pregnancy
Retained pregnancy products following a miscarriage or
termination
Ectopic pregnancy
Causes related to the ovaries:
Ovarian cysts with complications such as bleeding inside
a cyst
Twisted ovarian cyst
Ovarian tumours (cancer)
Causes related to the tubes:
Infection of the tubes
Other causes:
Appendicitis and other causes
Is ultrasound safe?
There are no known harmful effects associated with the medical use of sonography. Widespread clinical use of diagnostic ultrasound for many years has not revealed any harmful effects. Studies in humans have revealed no direct link between the use of diagnostic ultrasound and any adverse outcomes. Although the possibility exists that biological effects may be identified in the future, current information indicates that the benefits to patients far outweigh the risks, if any, that may be present.
What are the limitations
of the exam?
Because bone weakens sound waves, ultrasound cannot be used to examine bones surrounding your abdomen, such as your ribs. Also, because sound is weakened as it passes through layers of tissue, results from patients who are overweight are not of the same quality as those who are thin. In addition, ultrasound cannot obtain images through gas. Thus, bowel gas may limit visualization of some structures of interest. The ultrasound exam quality also depends on the examiner’s experience and the type of equipment used.
